PURPOSE: To obtain a hollow fiber module of high filling rate with significantly improved resistance against heat and chemical by sealing a gap between a sleeve and a bundled body as well as a gap between hollow fibers using a thermally fusible polymer sheet melting, at least, on one end of the bundled body of hollow fiber-like porous separation film.

CONSTITUTION: A gap between a sleeve and a bundled body, and a gap between hollow fibers are sealed using the melt 2 of a thermally fusible polymer sheet 4 at least on one end of the bundled body, in a hollow fiber module which stores the bundled body of hollow fiber-like porous separation films 3 in the sleeve. When manufacturing the hollow fiber module, each end of the separation films 3 is allowed to cross at right angles with the longitudinal direction of a belt-like sheet 4 of thermally fusible polymer with a specified width, on the sheet 4. Further, the ends of the film 3 are aligned in parallel at a specified interval between each other and the sheet 4 is wound into a roll in such a manner that each end of the separation film 3 comes inside. Finally the rolled sheet part of the roll is heated to allow the sheet 4 to melt.